Surgical correction of a craniofacial anomaly or dentofacial deformity is a complex procedure, particularly in patients with asymmetries. Even with the focus on post-surgical assessments of hard and soft tissue over the past decades, there are critical areas, such as maxillomandibular rotations and condylar/ramus resorbtion, that can not be evaluated with two-dimensional methods. The objectives of this prospective observational study that incorporates three-dimensional imaging (3-D) techniques are to characterize asymmetries more precisely prior to surgery, quantify areas of instability following facial surgical procedures, and improve pre-operative surgical planning. Since asymmetries are particularly difficult to ascertain and treatment plan, the agreement between clinical assessment of asymmetry location and its 3D characterization will be evaluated. In the 3D characterization, the surface distances between the 3-D models of the "affected" side of the mandible and the reflected mirror image of the "unaffected" side will be used to anatomically locate and estimate the asymmetry with two different mirroring techniques. An ancillary question is whether providing this information to surgeons alters the approach to the surgical correction. Surgeons will be trained in the use of 3D surgical simulation and the actual surgical outcome compared to the surgical simulation as one aspect of the validation of this method. In addition, this project will quantitatively assess 3D displacement and rotations of the jaws following orthognathic surgery for correction of asymmetry and Class III skeletal deformities. Voxel-wise rigid registration of the 3D cranial base surfaces will be used to avoid observer-dependent superimposition. The proposed work is multidisciplinary - incorporating treatment of craniofacial and dentofacial deformities, clinical research design and computer imaging. The combination of better planning of surgical treatment and identification of factors that contribute to the most successful treatment has great potential to improve treatment for some of the most difficult facial problems and dysmorphisms in the cranio-maxillofacial region. Involvement in these studies will enhance the candidate's prior training in cranio-maxillofacial problems and 3D imaging, while equipping her with tools to perform meaningful studies centered around patient oriented clinical research. [unreadable] [unreadable] [unreadable]